Alrighty guys, As some of you might remember, I had CEL lean problems when I replaced my 4 stock cats w/ high flows. So I replaced the front two O2 sensors and problem solved. Truck ran good for about a month and then CEL came on again and code says running lean B1S2. So I put an X-pipe on a couple of weeks ago and still running lean. It wouldn't bother me if the truck ran good but it doesn't half the time. Here's what it does: Cranks and idles fine, if I run like 10 mph it'll run & sound like a cam is on it, then runs strong until I let off the gas and it'll start to hesitate shudder until I mash the gas again, then when I slow down like to pull in the driveway it'll start spuddering. Does anybody know what I can do to get this truck running right? Should I replace the rear O2 sensors. Please help me out because gas mileage is suffering from this.

 

Could be the rear O2s, but sputtering? Sounds more like a fuel pump problem to me. Have you had a custom tune yet? All those miles and all those years and all those mods on that stock tune... yikes!

 

I thought the rear o2 sensors only read wether or not the converters were there.

 

Yeah, the spuddering could be a fuel pump isuue beings at 201,500 miles it's got the factory one still on. Thought about changing fuel filter again. Where do I get a custom tune and how much $?

I thought the same for the rear O2s but they've got 201,500 miles on them

Any other fixes out there?????

 

Troyer Performance, VMP, those are a couple of the more popular ones out there. Go over to the chips, tuning, and programming section and search up some stuff and make a thread explaining your problem now and mods and see what comes up. A guy that tunes the truck could also probably help you find the problem.

 

they read how your engines running..the first one reads how it is before the cat..the second one after the cat..if they read that same the CEL comes on...but if their old they can cause a problem..and a drop in MPG's

 

So you're saying if the rear 02s are bad or old which they are 201,500 miles old they could cause these problems? Maybe I should replace them

 

dont mean to sound like a jacka** but you probably shoulda changed em out when you changed the front 2...most people change all 4 at once..but yea man those suckers havin dang near 202,000 miles on em aint helpin much..if i were u id replace the back 2 as well im bout gettin ready to change mine out after 126,000 miles

 

Yeah I thought you changed the rear at the same time of changing the fronts. I didn't read your entire thread back then butI figured you did. Try that out and see if the key was the rear O2s.

 

Alrighty then I guess I'll pick up some rear 02s today. Also I was reading up on EGR valves and sounds like a bad one can cause rough idle and bucking at acceleration. Might need to look into this also. Do yall recommend cleaning it or buying a new one?

 

Cleaning it could help. If you can clean it before buying new, always take the more affordable route to clean it.

 

Ok thanks, now I read about the DPFE valve. Sounds like it and the EGR work together so maybe I should check it out also. What do you know about it?

 

I know absolutely nothing about any DPFE, lol sorry man. Thats a search for google.

 

Yeah, me neither. Google is where I was reading about it. Pretty interesting stuff. I'll clean the EGR valve first then worry about the DPFE. Any tips on cleaning the EGR valve?

 

I have never cleaned an EGR, if its anything like a port & polish for a TB, just be as patient as possible.